Distance vs. Time Graphs

Today in class we had a motion detector & we had a board so what the board was  a target for the motion detector.. We had had to walk forward & backword so it would know the time & position.When we stayed at the sam position the motion line would stay in a straight line, we moved back the position line would go higher , we moved in towards the motion detector the position line would go lower,so it depended on your movements you would get different results.

Why do i think these are necssecary is because when we measure motion we measure its speed interval & to see how many movements it would take to be at that certain amout of seconds. That is why i think these grapghs would be important to our science class